FDA Launches Probe into New Elevidys Death as Sarepta and Roche Face Ongoing Safety Concerns

The U.S. Food and Drug Administration (FDA) has initiated an investigation into the death of another patient who received Sarepta Therapeutics' Duchenne muscular dystrophy (DMD) gene therapy, Elevidys. This latest development adds to the growing list of safety concerns surrounding the treatment and its adeno-associated virus (AAV) platform.

Patient Death in Brazil Sparks FDA Investigation

Late Friday, the FDA announced its probe into the death of an 8-year-old boy in Brazil who was treated with Elevidys. The patient, who was not part of a clinical trial, passed away on June 7. Sarepta and its ex-U.S. partner Roche have stressed that the death is unlikely to be related to the gene therapy itself.

According to Brazil's health regulator, Anvisa, the fatality may have been caused by a severe flu infection, exacerbated by the immunosuppression regimen administered to gene therapy patients. This marks the third reported death in an Elevidys patient this year and the fourth for a person treated with a Sarepta gene therapy overall.

Regulatory Actions and Company Responses

In response to the recent safety concerns, Roche has paused shipments of Elevidys in Brazil. This decision follows similar moves by both Roche and Sarepta in other countries where Elevidys approvals were based on the FDA's decisions.

The FDA is now considering whether to require new analyses of Elevidys to confirm its safety. A Department of Health and Human Services spokesperson stated that the agency is "looking at all the tools we have" to evaluate the treatment's market position.

Despite the ongoing controversies, both Sarepta and Roche continue to stand behind Elevidys. Roche has expressed its intention to seek a path forward for the therapy in the European Union, following a recent rejection by the Committee for Medicinal Products for Human Use.

Implications for AAV-Based Gene Therapies

The recent string of patient deaths has raised concerns about the safety of AAV-based gene therapies in general. All three patients whose deaths were linked to a Sarepta gene therapy died from acute liver failure, a known side effect of AAV-based treatments.

Analysts from William Blair suggest that additional research and education may be needed regarding the risks associated with immunosuppression in the context of gene therapies. The situation also highlights the potential challenges of balancing treatment eligibility with seasonal health risks, as exemplified by the Brazilian patient who may have been treated expeditiously before aging out of eligibility during flu season.

As the FDA continues its investigation and considers potential regulatory actions, the pharmaceutical industry will be closely watching for any implications that may affect the development and approval of other AAV-based gene therapies in the pipeline.